The way I see it, an airlock is already essentially open fermentation. 1" of water is .036 psi. I doubt the yeast can tell the difference between 14.7 and 14.736 psi. So unless you're trying to introduce something wild (or are using 3 feet of water in your blowoff bucket), there's really no reason to change the standard process.

The way I see it, an airlock is already essentially open fermentation. 1" of water is .036 psi. I doubt the yeast can tell the difference between 14.7 and 14.736 psi. So unless you're trying to introduce something wild (or are using 3 feet of water in your blowoff bucket), there's really no reason to change the standard process.

i was not thinking of the psi angle but in a sense open fermentation has been the standard process for wits and hefeweizens for at least hundreds of years. beer in general for a lot longer. there is a definite difference between an open fermented beer and the new "standard" process. i'm certainly no expert but i would imagine that the risk of contamination is one of the few reasons this is no longer widely practiced. if the risk can be minimized then there is no reason not to do it, for me anyway. an increase in esters and phenols has been shown with open fermentation which is why i decided to see for myself with this experiment.*

disclaimer: i am not an brew scientist or expert just a wacko with a few sacks of grain, a grain mill, brewing equipment, books and some free time. i could be wrong about everything.

this is the first batch of beer where i saw no krausen at all. there is a thin ring of green (hop?) residue right at the top of the beer and that's it. the only thing i did differently is use fresh orange zest so i wonder if the oils prevented the krausen from forming? i'm not worried about the forming or non forming of krausen as it relates to fermentation but the science behind it forming or not. the gravity of the wort before i pitched the yeast (3/11/11) was 1.045 and the reading this morning (3/14/11) was 1.020 so it's moving along.

. . . an increase in esters and phenols has been shown with open fermentation which is why i decided to see for myself with this experiment.*

disclaimer: i am not an brew scientist or expert just a wacko with a few sacks of grain, a grain mill, brewing equipment, books and some free time. i could be wrong about everything.

Nothing wrong with experimentation. However, I think the increase in esters with open fermentation is in reference to the modern commercial practice of brewing under pressure in a sealed fermenter. If you think about it from a chemical perspective, a yeast cell sitting in a bucket/carboy with an airlock is in a nearly identical environment to one sitting in a truly open fermenter. The only difference would be for an open bucket where the significantly larger surface area might lead to some compounds evaporating off. However, since you're trying to increase the amount of "other" compounds in your beer, that doesn't seem like an asset.

I don't know about your setup (youtube's blocked at work), but my favorite "fermentation corner" happens to be in the basement where the spiders, whatever little bugs they're eating, dust from dryer lint, and countless other contaminants abound. I feel better having a lid on it, but if going "naked" works for you, have at it.

it tastes pretty good so far and it has the color, so far, that i was after. the room it's in does not have any real drafts or HVAC vent, the only real air currents are coming from the crack under the door and whatever comes throught the door when i open it. it's covered up now since my intention was to have it open only during the vigorous fermentaion period and that appears to be over. my next open fermentation batch will be a hefeweizen and i'm trying to get a wide, shallow vessel to ferment in which is what was traditionally used.

The way I see it, an airlock is already essentially open fermentation. 1" of water is .036 psi. I doubt the yeast can tell the difference between 14.7 and 14.736 psi. So unless you're trying to introduce something wild (or are using 3 feet of water in your blowoff bucket), there's really no reason to change the standard process.

The difference in "open" fermentation is not the removal of pressure, instead it is the natural gas exchange which changes the dissolved oxygen content in the fermenting beer. The theory is that this extra available oxygen allows the yeast to produce compounds they would not normally produce in standard oxygen-deficient beer conditions.